Abstract: A container for stackable articles includes a base assembly, a plurality of side assemblies, a top assembly, and a plurality of shelf assemblies. The base assembly, side assemblies, and top assembly are preferably constructed of a multiple layer, corrugated laminate, and are attachable to one another, defining an interior storage space. Each shelf assembly includes a plurality of shelf support members with a plurality of bearing portions adjacent and integral to each shelf support member. A plurality of shelf members are provided, wherein each shelf member is fixed about a respective bearing portion at each end of the shelf assembly. The shelf assemblies are secured to the sidewall assemblies, and positioned in the storage space to engage manufactured articles, for example sunroofs, positioned therein.

Abstract: Pressure trapped in an inactive hydraulic actuator can result in the actuator moving in a direction which is opposite to that desired upon subsequent activation. The present method detects a trapped pressure condition and takes remedial action before activating the hydraulic actuator for motion. The pressure differentials across valves that control the fluid flow to and from the hydraulic actuator are used to detect a trapped pressure condition. In response to that detection, a selected valve is initially opened in a manner that releases the trapped pressure while producing motion in the desired direction. After the trapped pressure condition has been resolved, one or more other valves are operated to produce the desired motion of the hydraulic actuator.

Abstract: A system operates a hydraulic actuator, such as a cylinder, in one of several modes that include powered extension and retraction, self-powering regeneration modes in which fluid exhausting from one cylinder chamber is routed into the other cylinder chamber, and cross function regeneration modes wherein the fluid exhausted from one actuator is routed in the supply conduit to power a different actuator. A controller determines which modes are viable based on existing system conditions and selects from among the viable available modes. That determination is a function of the desired velocity for the actuator, the hydraulic load on the actuator, and pressures in the supply and return hydraulic conduits. The system also can recover potential or kinetic energy through pressure intensification which recovered energy can be used to power another simultaneously active hydraulic function or to drive the prime mover via an over-center variable pump/motor.

Abstract: A member of a machine, such as a boom on construction equipment for example, is pivoted by a first actuator and has a length that is alterable by a second actuator. A control method allows an operator of the machine to command a point on the member to move along a straight line path. The operator command specifies velocities along two orthogonal axes and those velocities are transformed into an angular velocity and a length velocity for the member. The angular velocity and a length velocity then are converted into individual velocities for the first and second actuators. Each actuator is operated at its respective velocity to achieve the commanded movement of the member.

Abstract: A hydraulic system has an electrohydraulic valve that controls flow of fluid to operate a hydraulic actuator, such as a cylinder or motor. A set of characterization data is provided which describes performance of the electrohydraulic valve as a function of changes in differential pressure across that valve. The hydraulic system is operated by specifying desired movement of the hydraulic actuator and in response deriving a desired valve flow coefficient which designates a level of fluid flow through the electrohydraulic valve. A compensated control signal is produced from the desired valve flow coefficient and the characterization data, to counter act effects that changes in differential pressure have on flow of fluid. The electrohydraulic valve is activated in response to the compensated control signal.

Abstract: A servomechanism includes a controller which dynamically estimates the resistance of the solenoid coil in an electrohydraulic valve as part of determining a level of electric voltage to apply to open the valve. The servomechanism receives a current setpoint designating a desired electric current level and senses the actual level of current flowing through the coil. A proportional term is derived from the current setpoint and the actual level of current. Creation of a derivative term is based on the difference between the current setpoint and the actual level of current. A feedforward term is produced by estimating the resistance of the electrohydraulic valve and limiting the feedforward term to a predefined range of acceptable values. The proportional term, derivative term, and the feedforward term are summed to define a desired voltage level, and a PWM signal for driving the electrohydraulic valve is generated based on the desired voltage level.